/*----------------------------------------------------------------------* * RAK12035_SoilMoistureSensor.cpp - Arduino library for the Sensor * * version of I2C Soil Moisture Sensor version from Chrirp * * (https://github.com/Miceuz/i2c-moisture-sensor). * * * * Ingo Fischer 11Nov2015 * * https://github.com/Apollon77/I2CSoilMoistureSensor * * * * Ken Privitt 8Feb2026 * * Adapted for MeshCore Firmware Stack * * * * MIT license * * * * This file contains a collection of routines to access the * * RAK12035 Soil Moisture Sensor via I2C. The sensor provides * * Soil Temperature and capacitance-based Soil Moisture Readings. * * * *----------------------------------------------------------------------*/ #include "RAK12035_SoilMoisture.h" #include "MeshCore.h" #include /*----------------------------------------------------------------------* * Constructor. * *----------------------------------------------------------------------*/ // RAK12035_SoilMoisture(uint8_t addr) // // Accepts the I2C Address to look for the RAK12035 // Initializes the I2C to null (will be setup later in Wire.Begin() // // No hardware is touched in the constructor. // I2C communication is deferred until begin() is called. //------------------------------------------------------------------------------ RAK12035_SoilMoisture::RAK12035_SoilMoisture(uint8_t addr) { _addr = addr; // Save the sensor's I2C address _i2c = nullptr; // Bus not assigned yet; must be set in begin() } //------------------------------------------------------------------------------ // setup() //------------------------------------------------------------------------------ // setup(TwoWire &i2c) // // Assigns the I2C bus that this driver instance will use. This allows the // application to choose between Wire, Wire1, or any other TwoWire instance // supported by the platform. // // No I2C communication occurs here; setup() simply stores the pointer so that // begin() and all register‑level operations know which bus to use. //------------------------------------------------------------------------------ void RAK12035_SoilMoisture::setup(TwoWire &i2c) { _i2c = &i2c; // assigns the bus pointer _i2c->begin(); // Initialize the bus to Wire or Wire1 } //------------------------------------------------------------------------------ // RAK12035 Soil Moisture begin() //------------------------------------------------------------------------------ // // Performs initialization of the RAK12035 soil‑moisture sensor. This // routine assumes that the application has already selected the I2C bus via // setup() and that the bus has been initialized externally (Wire.begin()). // It uses the passed in I2C Address (default 0x20) // // *** This code does not supprt three sensors *** // The RAK12023 has three connectors, but each of the sensors attached must // all have a different I2C addresses. // This code has a function to set the I2C adress of a sensor // and currently only supports one address 0x20 (the default). // To support three sensors, EnvironmentSensorManager would need to be modified // to support multiple instances of the RAK12035_SoilMoisture class, // each with a different address. (0x20, 0x21, 0x22) // The begin() function would need to be modified to loop through the three addresses // // DEBUG STATEMENTS: Can be enabled by uncommenting or adding: // File: varients/rak4631 platformio.ini // Section example: [env:RAK_4631_companion_radio_ble] // Enable Debug statements: -D MESH_DEBUG=1 // //------------------------------------------------------------------------------ bool RAK12035_SoilMoisture::begin(uint8_t addr) { // MESH_DEBUG_PRINTLN("begin() - Start of RAK12035 initialization"); // MESH_DEBUG_PRINTLN("begin() - RAK12035 passed in Address %02X", addr); // 1. Ensure setup() was called if (_i2c == nullptr) { MESH_DEBUG_PRINTLN("RAK12035 ERROR: I2C bus not set!"); return false; } uint16_t _dry_cal = 200; uint16_t _wet_cal = 600; uint8_t _version = 0; uint8_t _addr; // The I2C address to be used (passed in parameter) /*------------------------------------------------------------------------------------------ * Set Calibration values - This is done with custom a firmware version * * USE the Build Flag: -D ENABLE_RAK12035_CALIBRATION = 1 * OR * Change the value to 1 in the RAK12035_SoilMoisture.h file * * Calibration Procedure: * 1) Flash the the Calibration version of the firmware. * 2) Leave the sensor dry, power up the device. * 3) After detecting the RAK12035 this firmware will display calibration data on Channel 3 * * Frequency = Current Capacitance Value * Temperature = Current Wet calibration value * Power = Current Dry calibration value * * 4) Click refresh several times. This will take a capacitance reading and if it is * greater than the current Dry value it will store it in the sensor * The value will bounce a little as you click refresh, but it eventually settles down (a few clicks) * the stored value will stabalize at it's Maximum value. * * 5) Put the sensor in water. * * 6) Click refresh several times. This will take a capacitance reading and if it is * less than the current Wet value it will store it in the sensor * The value will bounce a little as you click refresh, but it eventually settles down (a few clicks) * the stored value will stabalize at it's Minimum value. * * 7) The Sensor is now calibrated, turn off the device. * * 8) Reflash the device with the non-Calibration Firmware, Data will be shown on Channel 2 * *------------------------------------------------------------------------------------------ */ #if ENABLE_RAK12035_CALIBRATION uint16_t _wet = 2000; // A high value the should be out of the normal Wet range set_humidity_full(_wet); uint16_t _dry = 50; // A low value the should be out of the normal Dry range set_humidity_zero(_dry); #endif /*-------------------------------------------------------------------------------- * * Check if a sensor is present and return true if found, false if not present * *-------------------------------------------------------------------------------- */ if (query_sensor()) { MESH_DEBUG_PRINTLN("begin() - Sensor responded with valid version"); return true; } else { MESH_DEBUG_PRINTLN("begin() - Sensor version FAIL"); return false; } } /*--------------------------------------------------------------------------------- * * Below are all the routines to execute the various I2C commands supported * by the RAK12035 sensor * *--------------------------------------------------------------------------------*/ uint16_t RAK12035_SoilMoisture::get_sensor_capacitance() //Command 01 - (r) 2 byte { uint8_t buf[2] = {0}; if (!read_rak12035(SOILMOISTURESENSOR_GET_CAPACITANCE, buf, 2)) { MESH_DEBUG_PRINTLN("Function 1: get_capacitance() FAIL: Bad data returned = %02X %02X", buf[0], buf[1]); return (buf[0] << 8) | buf[1]; // return raw for debugging } uint16_t cap = (buf[0] << 8) | buf[1]; MESH_DEBUG_PRINTLN("Function 1: get_capacitance() SUCCESS: Capacitance = %d", cap); return cap; } uint8_t RAK12035_SoilMoisture::get_I2C_address() //Command 02 - (r) 1 byte { uint8_t addr = 0; if (!read_rak12035(SOILMOISTURESENSOR_GET_I2C_ADDR, &addr, 1)) { MESH_DEBUG_PRINTLN("Function 2: get_I2C_address() FAIL: Bad data returned = %02X", addr); return addr; // return raw for debugging } MESH_DEBUG_PRINTLN("Function 2: get_I2C_address() SUCCESS: I2C Address = %02X", addr); return addr; } bool RAK12035_SoilMoisture::set_sensor_addr(uint8_t addr) //Command 03 - (w) 1 byte { if (!write_rak12035(SOILMOISTURESENSOR_SET_I2C_ADDR, &addr, 1)) { MESH_DEBUG_PRINTLN("Function 3: set_I2C_address() FAIL: Could not set new address %02X", addr); return false; } MESH_DEBUG_PRINTLN("Function 3: set_I2C_address() SUCCESS: New address = %02X", addr); return true; } uint8_t RAK12035_SoilMoisture::get_sensor_version() // Command 04 - 1 byte { uint8_t v = 0; read_rak12035(SOILMOISTURESENSOR_GET_VERSION, &v, 1); if (!read_rak12035(SOILMOISTURESENSOR_GET_VERSION, &v, 1)) { MESH_DEBUG_PRINTLN("Function 4: get_sensor_version() FAIL: Bad data returned = %02X", v); return v; } MESH_DEBUG_PRINTLN("Function 4: get_sensor_version() SUCCESS: Version = %02X", v); return v; } float RAK12035_SoilMoisture::get_sensor_temperature() //Command 05 - (r) 2 bytes { uint8_t buf[2] = {0}; if (!read_rak12035(SOILMOISTURESENSOR_GET_TEMPERATURE, buf, 2)) { MESH_DEBUG_PRINTLN("Function 5: get_temperature() FAIL: Bad data returned = %02X %02X", buf[0], buf[1]); return (buf[0] << 8) | buf[1]; // raw data returned for debugging 0XFFFF is error } // Sensor returns a 16-bit signed integer (°C * 10) int16_t raw = (buf[0] << 8) | buf[1]; float tempC = raw / 10.0f; MESH_DEBUG_PRINTLN("Function 5: get_temperature() SUCCESS: Raw=%04X Temp=%.1f C", raw, tempC); return tempC; } bool RAK12035_SoilMoisture::sensor_sleep() //Command 06 - (w) 1 byte { uint8_t tmp = 0; if (!write_rak12035(SOILMOISTURESENSOR_SET_SLEEP, &tmp, 1)) { MESH_DEBUG_PRINTLN("Function 6: sensor_sleep() FAIL: Could not send sleep command"); return false; } MESH_DEBUG_PRINTLN("Function 6: sensor_sleep() SUCCESS: Sensor acknowledged sleep command"); // Optional: turn off sensor power AFTER successful sleep command // This has been commented out due to a pin name conflict with the Heltec v3 // This will need to be resolved if this funstion is to be utilized in the future /* digitalWrite(WB_IO2, LOW); */ return true; } bool RAK12035_SoilMoisture::set_humidity_full(uint16_t full) //Command 07 - (w) 2 bytes { uint8_t buf[2]; buf[0] = (full >> 8) & 0xFF; // High byte buf[1] = full & 0xFF; // Low byte if (!write_rak12035(SOILMOISTURESENSOR_SET_WET_CAL, buf, 2)) { MESH_DEBUG_PRINTLN("Function 7: set_humidity_full() FAIL: Could not set wet calibration value" ); return false; } MESH_DEBUG_PRINTLN("Function 7: set_humidity_full() SUCCESS: New Full = %04X", full); return true; } bool RAK12035_SoilMoisture::set_humidity_zero(uint16_t zero) //Command 08 - (w) 2 bytes { uint8_t buf[2]; buf[0] = (zero >> 8) & 0xFF; // High byte buf[1] = zero & 0xFF; // Low byte if (!write_rak12035(SOILMOISTURESENSOR_SET_DRY_CAL, buf, 2)) { MESH_DEBUG_PRINTLN("Function 8: set_humidity_zero() FAIL: Could not set dry calibration value"); return false; } MESH_DEBUG_PRINTLN("Function 8: set_humidity_zero() SUCCESS: New Zero = %04X", zero); return true; } uint8_t RAK12035_SoilMoisture::get_sensor_moisture() //Command 09 - (r) 1 byte { // Load calibration values from sensor _wet_cal = get_humidity_full(); _dry_cal = get_humidity_zero(); MESH_DEBUG_PRINTLN("Function 9: get_moisture() - Read from sensor or calculate from capacitance"); // Read sensor version uint8_t v = get_sensor_version(); // If version > 2, read moisture directly from the sensor if (v > 2) { MESH_DEBUG_PRINTLN("Version > 02 - Reading moisture directly from sensor"); uint8_t moisture = get_sensor_humid(); MESH_DEBUG_PRINTLN("get_moisture() Direct Read = %d%%", moisture); return moisture; } // Otherwise calculate moisture from capacitance MESH_DEBUG_PRINTLN("Calculating moisture from capacitance"); uint16_t cap = get_sensor_capacitance(); // Clamp capacitance between calibration points if (_dry_cal < _wet_cal) { if (cap <= _dry_cal) cap = _dry_cal; if (cap >= _wet_cal) cap = _wet_cal; float pct = (_wet_cal - cap) * 100.0f / (_wet_cal - _dry_cal); if (pct > 100.0f) pct = 100.0f; MESH_DEBUG_PRINTLN("get_moisture Case 1() Calculated = %d%%", (uint8_t)pct); return (uint8_t)pct; } else { if (cap >= _dry_cal) cap = _dry_cal; if (cap <= _wet_cal) cap = _wet_cal; float pct = (_dry_cal - cap) * 100.0f / (_dry_cal - _wet_cal); if (pct > 100.0f) pct = 100.0f; MESH_DEBUG_PRINTLN("get_moisture Case 2() Calculated = %d%%", (uint8_t)pct); return (uint8_t)pct; } } uint8_t RAK12035_SoilMoisture::get_sensor_humid() //Command 09 - (r) 1 byte { uint8_t moisture = 0; if (!read_rak12035(SOILMOISTURESENSOR_GET_MOISTURE, &moisture, 1)) { MESH_DEBUG_PRINTLN("Function 9: get_sensor_humid() FAIL: Bad data returned = %02X", moisture); return moisture; // raw fallback } MESH_DEBUG_PRINTLN("Function 9: get_sensor_humid() SUCCESS: Moisture = %d%%",moisture); return moisture; } uint16_t RAK12035_SoilMoisture::get_humidity_full() //Command 0A - (r) 2 bytes { uint8_t buf[2] = {0}; if (!read_rak12035(SOILMOISTURESENSOR_GET_WET_CAL, buf, 2)) { MESH_DEBUG_PRINTLN("Function A: get_humidity_full() FAIL: Bad data returned = %02X%02X", buf[0], buf[1]); return 0xFFFF; // error indicator } uint16_t full = (buf[0] << 8) | buf[1]; MESH_DEBUG_PRINTLN("Function A: get_humidity_full() SUCCESS: Full = %04X = %d", full, full); return full; } uint16_t RAK12035_SoilMoisture::get_humidity_zero() //Command 0B - 2 bytes { uint8_t buf[2] = {0}; if (!read_rak12035(SOILMOISTURESENSOR_GET_DRY_CAL, buf, 2)) { MESH_DEBUG_PRINTLN("Function B: get_humidity_zero() FAIL: Bad data returned = %02X%02X", buf[0], buf[1]); return 0xFFFF; // error indicator } uint16_t zero = (buf[0] << 8) | buf[1]; MESH_DEBUG_PRINTLN("Function B: get_humidity_zero() SUCCESS: Zero = %04X = %d", zero, zero); return zero; } /*------------------------------------------------------------------------------------------* * getEvent() - High-level function to read both moisture and temperature in one call. * *------------------------------------------------------------------------------------------* * This function reads the moisture percentage and temperature from the sensor and returns * * them via output parameters. This may be used for the telemerty delivery in the MeshCore * * firmware, with a single function to get all sensor data. * * * * The function returns true if both readings were successfully obtained, or false if any * * error occurred during I2C communication. * * * * This function is currently not used * *------------------------------------------------------------------------------------------*/ bool RAK12035_SoilMoisture::getEvent(uint8_t *humidity, uint16_t *temp) { // Read moisture (0-100%) uint8_t moist = get_sensor_moisture(); if (moist == 0xFF) //error indicator return false; MESH_DEBUG_PRINTLN("getEvent() - Humidity = %d", moist); *humidity = moist; //Read temperature (degrees C) uint16_t t = get_sensor_temperature(); if (t == 0XFFFF) // error indicator return false; *temp = t; MESH_DEBUG_PRINTLN("getEvent() - Temperature = %d", t); return true; } /*------------------------------------------------------------------------------------------* * Sensor Power Management and Reset Routines * * These routines manage the power and reset state of the sensor. The sensor_on() routine is * designed to power on the sensor and wait for it to become responsive, while the reset() * routine toggles the reset pin and waits for the sensor to respond with a valid version. * * They are for a future sensor power management function. *------------------------------------------------------------------------------------------*/ bool RAK12035_SoilMoisture::sensor_on() { uint8_t data; // This has been commented out due to a pin name conflict with the Heltec v3 // This will need to be resolved if this funstion is to be utilized in the future /* pinMode(WB_IO2, OUTPUT); digitalWrite(WB_IO2, HIGH); //Turn on Sensor Power pinMode(WB_IO4, OUTPUT); //Set IO4 Pin to Output (connected to *reset on sensor) digitalWrite(WB_IO4, LOW); //*reset - Reset the Sensor delay(1); //Wait for the minimum *reset, 1mS is longer than required minimum digitalWrite(WB_IO4, HIGH); //Deassert Reset delay(10); // Wait for the sensor code to complete initialization */ uint8_t v = 0; time_t timeout = millis(); while ((!query_sensor())) //Wait for sensor to respond to I2C commands, { //indicating it is ready if ((millis() - timeout) > 50){ //0.5 second timeout for sensor to respond MESH_DEBUG_PRINTLN("reset() - Timeout, no response from I2C commands"); return false; } else { delay(10); //delay 10mS } } } bool RAK12035_SoilMoisture::reset() { // This function is for a future Sensor Power Management function. // When power is reapplied this will reset the sensor and wait for it to respond // with a valid version. // // The Atmel 8495 Microcoltroller: Reset input. A low level on this pin for longer than // the minimum pulse length will generate a reset, even if the clock is not // running and provided the reset pin has not been disabled. The minimum pulse length is // given in Table 25-5 on page 240. 2000ns = .002mS // Shorter pulses are not guaranteed to generate a reset. // // Power is never removed so the Sensor reset was removed and is not needed, // But might be needed if power is ever switched off. Here is tested code. // This has been commented out due to a pin name conflict with the Heltec v3 // This will need to be resolved if this funstion is to be utilized in the future /* pinMode(WB_IO4, OUTPUT); //Set IO4 Pin to Output (connected to *reset on sensor) MESH_DEBUG_PRINTLN("Assert *reset (Low) for 1 mS"); digitalWrite(WB_IO4, LOW); //Reset the Sensor delay(1); //Wait for the minimum *reset, 1mS is longer than required minimum MESH_DEBUG_PRINTLN("reset() - De-assert *reset (High)"); digitalWrite(WB_IO4, HIGH); // Deassert Reset */ MESH_DEBUG_PRINTLN("reset() - Begin poling in 100mS intervals for a non-zero version"); uint32_t start_time = millis(); MESH_DEBUG_PRINTLN("reset() - Timeout, Start Time: %d milliseconds", start_time); const uint32_t timeout_ms = 500; // Wait for 0.5 seconds uint32_t start = millis(); while (true) { if (query_sensor()) { MESH_DEBUG_PRINTLN("reset() - First Pass, Sensor responded with valid version"); uint32_t stop_time = millis(); MESH_DEBUG_PRINTLN("reset() - Timeout, Stop Time: %d mS", stop_time); MESH_DEBUG_PRINTLN("reset() - Timeout, Duration: %d mS", (stop_time - start_time)); return true; } if (millis() - start > timeout_ms) { MESH_DEBUG_PRINTLN("reset() - Timeout waiting for valid sensor version"); uint32_t stop_time = millis(); MESH_DEBUG_PRINTLN("reset() - Timeout, Stop Time: %d mS", stop_time); MESH_DEBUG_PRINTLN("reset() - Timeout, Duration: %d mS", (stop_time - start_time)); return false; } delay(100); } } bool RAK12035_SoilMoisture::query_sensor() { uint8_t v = 0; v = get_sensor_version(); // Treat 0x00 and 0xFF as invalid / bootloader / garbage if (v == 0x00 || v == 0xFF) { MESH_DEBUG_PRINTLN("query_sensor() FAIL: Version value invalid: %02X", v); return false; } MESH_DEBUG_PRINTLN("query_sensor() SUCCESS: Sensor Present, Version = %02X", v); return true; } /*------------------------------------------------------------------------------------------* * Below are the low-level I2C read and write functions. These handle the actual * communication with the sensor registers. The higher-level functions call these * to perform specific tasks. *------------------------------------------------------------------------------------------*/ bool RAK12035_SoilMoisture::read_rak12035(uint8_t cmd, uint8_t *data, uint8_t length) { _i2c->beginTransmission(_addr); _i2c->write(cmd); // <-- COMMAND, not register index if (_i2c->endTransmission() != 0) return false; delay(20); int received = _i2c->requestFrom(_addr, length); if (received != length) return false; for (int i = 0; i < length; i++) data[i] = _i2c->read(); return true; } bool RAK12035_SoilMoisture::write_rak12035(uint8_t cmd, uint8_t *data, uint8_t length) { _i2c->beginTransmission(_addr); _i2c->write(cmd); // <-- COMMAND, not register index for (uint8_t i = 0; i < length; i++) _i2c->write(data[i]); if (_i2c->endTransmission() != 0) return false; delay(20); return true; }